"Arrow" Season 4 will likely feature a death of a major character in the midseason finale, a new villain added to the cast and Roy Harper/Arsenal's return to the show.

"San Andreas" star Colton Haynes has confirmed his return as Roy Harper/Arsenal in "Arrow" TV series when he tweeted on his Twitter page that he began filming his scenes for an episode for season 4 in Vancouver. Haynes first teased his return to the show during the AsiaPop Comic Con event in Manila, Philippines and even going so far as to making an appearance in the spin off show, "Legends of Tomorrow".

Comic book fans last saw Roy Harper in season 3 as he leaves Star City after he was presumed dead by the public. He then gave his Arsenal costume to Thea Queen (Willa Holland), thus becoming a viglante known as Speedy..

Aside from Roy Harper's return, a new villain has been added to season 4 as "Everwood" and "Saving Lincoln" actor Tom Amandes joins the cast as the super villain the Calculator, WeGotThisCovered reported.

Amandes' character will be in the same episode as Haynes as Noah Kuttler/the Calculator uses his advance knowledge on computer science and manipulation to blackmail Roy Harper and will eventually lead to a reunion of sorts with Oliver Queen/Green Arrow (Stephen Amell) and the rest of Team Arrow.

Lastly, several rumors are making rounds that the midseason finale for "Arrow" season 4 will likely feature the death of a major character within the show.

The show's executive producer Wendy Mericel stated that the death of a major character could happen sooner than the audiences expected. Audiences were already given a glimpse that character's death in first episode as Oliver swore revenge against Damien Darhk (Neil McDonough) for killing one of his closest friends, TV Line reported.

The synopsis for the midseason finale in "Arrow" season 4 will have Oliver and Team Arrow take the fight to Damien Darhk and and his organization. Darhk will retaliate in a brutal fashion when attacks Oliver during his mayoral holiday party, which likely have the death of a major character.

The list characters that will likely die in the midseason finale could be Felicity Smoak (Emily Bett Rickards), John Diggle (David Ramsey) and Captain Quentin Lance (Paul Blackthorne).

"Arrow" season 4 airs on Wednesdays at 8/7pm central on the CW Network.